Improvement in millstone-staffs



G. T. SMITH.

MILLSTQNE-STAFF. No 169 858, Patented Nov.9, 1875.

N. PETERS. PHOTO LITMOGRAPFER of the stone to a straight, or one or more of them may be made j to a satisfactory face by the use of the circular wooden staff, thevcentral GEORGE T. SMITH, 0E

PATENT OFFICE.

ST. LOUIS, MISSOURI.

IMPROVEMENT IN IV IILLSTONE-STAFFS.

Specification forming part of Letters Patent No 169,858, dated November 9, 1875; application filed September 1, 1875.

To all whom it may concern:

Be it known that I, GEORGE T. SMITH, of St. Louis, in the county of St. Louis and State of Missouri, have invented certain new and useful Improvements in MillstoneStaff; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accom panyin g drawings, and to the letters of reference marked thereon, which form a part of this specification.

Figure 1 represents a circular proof-staff. Fig. 2 is the wooden working or red staff, as it is sometimes called. Fig. 3 represents a long square staff, similar to those in common use among millers, and Fig. 4 is a transverse section, Fig. 2.

My invention is designed to enable the miller to reduce the skirt or outer grinding-face perfectly flat or plane surface, and at the same time to dress the central portion or eye to such height or face relative to the skirt as his judgment shall decide is advisable.

In Fig. 1, A is the body of the proof-staff, the lower face of which is reduced to a plane by any usual or preferred method, although I usually employ the'method of grinding set forth in my application of earlier date. a are radial arms or ribs cast upon the back of the staff, for the purpose of insuring that it shall not spring'or he accidentally warped.

The proof-staff shown in Fig. 2 is made of successive layers of wood, so arranged that the grain of each layer shall cross that of the adjacent layer or layers.

The working face of this staif is reduced to a plane, using the metal staff as a test or proof, as will be readily understood.

The sides of the long staff, Fig. 3, may be slightly convex. After the skirt of a stone has been dressed portion may be worked down by using the long staff in the following manner Paint only the central part of this staff, and when it is on the stone swing it slowly around without allowing either end to project beyond the hoop of the stone, and dress 05 each time such portions as are painted. The result will be that the height of the central part or eye will be determined by the plane of the skirt, as the ends of the staff will ride upon thisskirt, and if care be taken to paint only such part of the staff as will correspond to the inner diameter of the circular staff, a belt or skirt of uniform width and in a perfect plane, will be formed, and the eyewill be very nearly uniform in its plane relative to the skirt-that is to say, supposing the long staff to be of a slight but regular curve on its working face, then all the radial lines will be in a common plane from their inner starting-points until they reach the skirt of the stone. This operation requires that the long staff should be of a length corresponding to the diameter of the stone; but where this isimpracticable care should be taken to place the staff centrally upon the stone, and in swinging it around keep its ends equidistant from the outer edge.

In case greater accuracy is desired in keeping the skirt of the stone of uniform width, two colors of paint may be employed, and after the central portion has been staffed with one color-say, with red-blue may be applied with the circular staff, which will indicate clearly the line to which the eye or breast should be dressed.

I have found that twodifficulties grow out of the weight of a wooden staff when it is made solid; first, it is heavy to handle, and, secondly, it wears away so fast where it touches upon the high spots of the stone, that it requires to be frequently proved.

In order to obviate these two objections, and also to lessen the liability of its becoming warped from absorbing moisture and drying out, I have made it hollow, or partially hollow, and, by preference, I leave intervening walls between cavities, as shown in Fig. 2.

I do not in this patent claim, broadly, the idea of proving or testing the face of a millstone by means of a circular stafl, 'as thatforms'the sub ect of another a tofore filed by me.

What I claim is--- The herein-described method of proving or pplication heredetermining the face of a millstone by the use, In testimony-that I claim the foregoing as first, of a circular stafif, Fig. 2, which is einmy own,lhaveaffixed my signatureinpresence ployed to level the skirt; and, second, of a of two Witnesses.

long staff, Fig. 3, to establish the height or plane of the eye or central part of the stone GEORGE T. SMITH. relative to the skirt, said. skirt serving as a Witnesses: guide for the ends of the long staff, substan- H. H. DOUBLEDAY,

tially as set forth. S. G. TIBBITTS. 

